Any exotic bird experts out there?

I have a very friendly Rose ed atoo and he is wonderful with other birds that he has met. He has gotten along with a macaw, eclectus and a larger atoo. I have been wanting to get another bird, and came across a blue Ringneck, i am wondering if i should go and meet the ringneck with my bird or not. I cant tell if the ringneck is much smaller then my atoo (the rose ed are the smallest of the atoos) By looking at pix of ringnecks and the rose ed on peoples shoulders and comparing them, the ringneck does not seem too much smaller then my atoo, any pros out there? Does anyone have both these birds or know enough about both. Any knowledgeable info would be great.